Innovative Mineral Block Improves Poultry Welfare

Bio-Genesys has developed an innovative mineral block for chickens. Intended as an alimentary supplement, the Avipeck block provides a ‘choice feeding’ regimen and has been demonstrated to improve not only nutrition but also welfare, in several important ways. It was initially formulated as an anti-stress product and preventive for behavioural problems, such as pecking and feather pulling. Qualitative observations have indicated the success of the block for this purpose. Furthermore, initial trials have quantitatively demonstrated a positive impact on skeletal development, with stronger leg bones leading to better welfare for the birds. 

Choice feeding 

Evidence suggests that chickens are able to regulate their intake of minerals according to their varying needs throughout the day1,2. Avipeck helps birds to adapt the intake of minerals to their particular metabolic needs, promoting the optimisation and nutritional efficiency of the feed. This has implications for production: initial trials with Avipeck for layers found significantly higher egg weight compared to a control group and whilst the mean overall egg shell density remained unchanged in young first crop hens, it increased in older second crop hens.


Trial indicates improved welfare 

A full trial of the Avipeck block for broilers was carried out under the supervision of the Royal Veterinary College, London. 23,981 birds were given access to an Avipeck block in addition to their normal feeding regime, at a rate of one 18kg block to every 800 birds, or 30 blocks in total.

A control group of 23,789 birds was reared under the same conditions but without access to the block, for comparison. No significant differences were found in total feed intake (i.e. normal dietary regime), water intake, feed conversion rates or final weight. However, there was evidence for behavioural changes in the birds and at the end of the trial, organ weights were found to be significantly different, with the Avipeck group 4% heavier than the controls. It is commonly known and accepted that internal organ weight is an indication of health. Furthermore, significant differences were found in bone strength and volumes, indicating improved skeletal development in the Avipeck group. 

Tail pecking and feather pulling 

One of the main aims behind developing the block was to reduce the incidence of behavioural problems such as tail pecking and feather pulling. Feather pecking is very different from aggressive pecking and has different causes and effects. The movements are not rapid, but deliberate and at the most extreme, the feathers are grasped and then pulled3. It is thought to be triggered by nutritional deficiencies in protein and amino acids, especially if there are signs of the feathers being eaten, but it can also be a behavioural response to ‘boredom’: the problem is worse when there is a lack of sufficient stimuli for the birds. The Avipeck blocks are formulated to be durable and incorporate novel flavours (geranium and orange essential oils) that are attractive to the birds, to mitigate boredom that may lead to tail pecking. Anecdotal evidence from farm hand observations during the Avipeck trials suggest that access to the blocks makes the birds generally calmer, with fewer signs of tail-pecking. Furthermore, when the carcasses were examined at the end of the trial, scratches were found to be significantly lower in the Avipeck group (11%) compared to the control birds (18%), which would indicate that less fighting and aggression had taken place. 

Improved skeletal development 

Modern intensive poultry production systems have given rise to two main skeletal disorders affecting the welfare of chickens: osteoporosis in egg-laying hens and leg problems in broilers due to extremely rapid growth, such as tibial dyschondroplasia, rickets and other deformities causing lameness4. Tibial dyschondroplasia is a disease of young poultry that affects the growth of bone and cartilage. It usually displays no clinical signs unless the condition is severe, when it can lead to swelling and bowing in the knee joint region, and to lameness5. It can be prevented by modifying calcium and phosphorus ratios, vitamin D3 supplementation, chloride levels and the acid/ base balance. 

The Avipeck blocks include calcium from various sources (including CaCO3), inorganic P and vitamin D3, and were provided to the chicks from one day old. There is evidence that limestone fed as particulates benefits skeletal and eggshell quality5. The blocks also contain sodium, which is known to be beneficial for the formation of strong bones. 

At six weeks of age, the broilers were processed and chilled at 4°C overnight before deboning. Post-mortem measurements found significantly higher bone volume, density and breaking strength compared to the control group. This is a crucial welfare result as it directly translates to lower incidence of impaired walking ability, tibial dyschondroplasia or broken bones. Bone parameters for significant differences are given in the table below, where P<0.001 in all cases. 

Campylobacter reduction 

There is good reason to think that the Avipeck block could be useful as part of a campylobacter reduction campaign, since it contains coarse rolled wheat particles.

Fibre is important in chicken diets as it affects the development and pH of the gastrointestinal tract, in turn impacting on the bacterial population6,7. In particular, Moen et al. (2012) showed that by stimulating the birds’ natural barriers in their upper digestive tract with a diet supplemented with 15% oat/barley hulls for structure, the spread of Camp. jejuni within the group was delayed and the relative amount of Camp. jejuni in the caecum was reduced, compared with the control diet8

Future studies with Avipeck are currently being planned to see if the block can help to control campylobacter, particularly when used alongside other Bio-Genesys hygiene products such as Desysec sanitiser for animal bedding and litter. 

Michelle Doherty BA BSc(Hons) PhD

The Avipeck block is sold through the UK and Europe. For more information contact



Henuk Y.L. and Dingle J.G. (2002), Practical and economic advantages of choice feeding systems for laying poultry, World’s Poultry Science Journal, 58, pp 199-208 
Pousga S, Boly H and Ogle B (2005), Choice feeding of poultry: a review. Livestock Research for Rural Development. Vol. 17, Art. #45 
Appleby M.C., Hughes B.O. and Mench J.A. (2004), ,Poultry Behaviour and Welfare, Cabi Publishing 
Fleming R.H. (2008), Nutritional factors affecting poultry bone health, Proc Nutr Soc. 67(2):177-83 , last accessed on 29 October 2015. 
Jimenez-Moreno E., Gonzalez-Alvarado J.M., de Coca-Sinova A., Lazaro R., Mateos G.G. (2009) , Effects of source of fibre on the development and pH of the gastrointestinal tract of broilers, Animal Feed Science and Technology, 154 (1-2) , pp. 93-101. 
Gonzalez-Alvarado J.M., Jimenez-Moreno E., Gonzalez-Sanchez D., Lazaro R., Mateos G.G. (2010), Effect of inclusion of oat hulls and sugar beet pulp in the diet on productive performance and digestive traits of broilers from 1 to 42 days of age, Animal Feed Science and Technology, 162 (1-2) , pp. 37-46 
Moen, B., Rudi, K., Svihus, B. and Skånseng, B. (2012), Reduced spread of Campylobacter jejuni in broiler chickens by stimulating the bird’s natural barriers. Journal of Applied Microbiology, 113: 1176–1183. 


Date: 18/03/2016
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